Generally speaking, it is known that under certain conditions, aluminum reacts with water to generate hydrogen and heat. It is also known, however, that this type of reaction is not sustainable at ambient temperature. It is believed that a protective oxide layer forms on a metal surface in contact with water at ambient temperature and hampers the reaction. Therefore, it has been accepted by those skilled in the art that the use of aluminum in a reaction with water to generate heat and hydrogen gas requires that the protective oxide layer is efficiently and continuously removed, and that the reaction is kept at an elevated temperature.
A number of hydrogen generators have been developed in the past. The following patent documents constitute a good inventory of the devices and methods of the prior art in the field of hydrogen gas generation using the reaction of aluminum or alloys of aluminum with water.
U.S. Pat. No. 909,536 issued on Jan. 12, 1909, and U.S. Pat. No. 934,036 issued on Sep. 14, 1909, both issued to G. F. Brindley et al. These documents disclose several compositions for generating hydrogen. The compositions comprise any metal which can form an hydroxide when it is brought into contact with a solution of a suitable hydroxide. For example, aluminum is reacted with sodium hydroxide to release hydrogen and produce sodium aluminate.
U.S. Pat. No. 2,721,789, issued on Oct. 25, 1955 to Q. C. Gill. This document discloses the structure of an hydrogen generator for reacting water with a measured dry charge of aluminum particles and flakes of sodium hydroxide. The reaction releases hydrogen gas and produces sodium aluminate.
U.S. Pat. No. 3,554,707 issued on Jan. 12, 1971 to W. A. Holmes et al. This document discloses a gas generator having bellows to raise or lower the level of water in response to the pressure inside the generator. As the level of water drops, the contact surface between the fuel cartridge and the water is lost and the reaction is terminated.
U.S. Pat. No. 3,957,483 issued on May 18, 1976 to M. Suzuki. This patent discloses a magnesium composition which produces hydrogen upon contact with water. The preferred magnesium composition comprises magnesium, and one or more metals selected from the group consisting of iron, zinc, chromium, aluminum and manganese.
U.S. Pat. No. 3,975,913 issued on Aug. 24, 1976 to D. C. Erickson. This document discloses a hydrogen generator wherein molten aluminum is reacted with water. The generator is kept at a very high temperature to keep the metal in a molten condition.
U.S. Pat. No. 4,643,166 issued on Feb. 17, 1987, and U.S. Pat. No. 4,730,601 issued on Mar. 15, 1988 both to H. D. Hubele et al. These documents disclose the structure of a fuel cell for producing heat energy and hydrogen gas. The device has a reaction chamber containing a fuel composition that is reactive with water. The fuel composition includes a main fuel part of magnesium and aluminum in a molar ratio of 1:2, and the second part is composed of lithium hydride, magnesium and aluminum in equal molar ratio.
U.S. Pat. No. 4,670,018 issued on Jun. 2, 1987, and U.S. Pat. No. 4,769,044 issued on Sep. 6, 1988, both to J. H. Cornwell. These documents describe a log made of compressed wood waste and paper. The log is coated with aluminum particles. Upon burning, the aluminum particles react with moisture in the log to emit heat due to the generation of hydrogen gas.
U.S. Pat. No. 4,752,463 issued on Jun. 21, 1988 to K. Nagira et al. This document discloses an alloy which reacts with water for producing hydrogen gas. The alloy material comprises essentially aluminum and 5 to 50% tin.
U.S. Pat. No. 5,143,047 issued on Sep. 1, 1992 to W. W. Lee. This document discloses an apparatus and a method for generating steam and hydrogen gas. In this apparatus, an aluminum or aluminum alloy powder is reacted with water to generate hydrogen gas. An electric power source is used to start the reaction. The electric power source is used to explode an aluminum conductor and to disperse pieces of molten aluminum into a mixture of water and aluminum powder. A heat exchanger is provided to extract useful heat.
U.S. Pat. No. 5,867,978 issued on Feb. 9, 1999 to M. Klanchar et al. This document discloses another hydrogen gas generator using a charge of fuel selected from the group consisting of lithium, alloys of lithium and aluminum. The charge of fuel is molten and mixed with water to generate hydrogen gas.
JP 401,208,301 issued to Mito on Aug. 22, 1989. This document discloses a process for producing hydrogen. Aluminum is reacted with water under an inactive gas or a vacuum to produce hydrogen gas.
CA 2,225,978 published on Jun. 29, 1999 by J. H. Checketts. This patent application discloses a hydrogen generation system wherein a coating on reactive pellets is selectively removed to expose the reactive material to water for producing hydrogen gas on demand. In one embodiment, aluminum and sodium hydroxide are reacted with water to release hydrogen gas and produce sodium aluminate.
Various other processes to produce hydrogen gas have been described in the art, as reacting water with magnesium, sodium, potassium, lithium, calcium, iron, zinc or steel.
Although the hydrogen production processes of the prior art deserve undeniable merits, it is believed that the catalytic reaction of aluminum and water, using sodium hydroxide as the catalyst, to release hydrogen gas from water at room temperature has never been anticipated or observed and disclosed by prior inventors. It is also believed that the prior art is short of suggestion with regards to a hydrogen production process which can be readily used to hydrogenate the fuel of engines and burners.
As such, it will be appreciated that there continues to be a need for a production process and for an apparatus for generating hydrogen gas using a simple and economical reaction which can be started at room temperature and carried out safely by ordinary persons not having a formal education in chemistry and chemical processes.